Method for producing a deflectable insertion tool

ABSTRACT

A method of producing a bendable tip for an instrument, is provided, which includes: mounting a tube for an instrument in a CNC controlled rotational and axially movable holder of a laser cutting machine, with a distal end of the tube extending form the holder; activating a laser cutter; cutting wedge shaped partial circumferential openings in the tube to define a plurality of radially extending ribs at the distal end of the tube, with the ribs being connected together by an axially extending spine, and the ribs having first and second axial sides; during cutting, forming in each of the ribs in at least one of the first or second axial sides, at least one of an axial projection or a recess, and forming in a facing one of the at least one of the first or second axial sides of an adjacent one of the ribs at least one of a corresponding complementary mating recess or a corresponding axial projection.

INCORPORATION BY REFERENCE

The following documents are incorporated herein by reference as if fullyset forth: U.S. Provisional Patent Application No. 62/490,202, filedApr. 26, 2017.

FIELD OF THE INVENTION

The present invention is related to a method of producing insertioninstruments, more specifically to a method for producing medicalinsertion instruments, and in particular to an ENT tool for use intreatment of a paranasal sinus or other ear, nose, and throatapplications.

BACKGROUND

Endoscopic sinus procedures, including surgery, are commonly used totreat chronic sinusitis. In many procedures, an endoscope is insertedinto the nostril along with one or more surgical instruments. In certainprocedures the insertion and subsequent withdrawal of a balloon into thetubular sinus passages is required. In other procedures, surgicalinstruments are inserted to cut and/or ablate tissue in order to improvedrainage from the sinus cavity.

In order to reach access points of the various sinus cavities, ENTphysicians typically use a tool set with multiple tools specificallyadapted for insertion or guiding of instruments, each with a differentangle, in order to allow the proper access to the desired site. Thephysician has to select the correctly angled tool or replace the tip ofthe tool with the correctly angled instrument, which can be cumbersomeand involves additional costs.

It has been suggested to use a steerable or bendable tip for certain ENTtools. However, the flexible ends or tips of these known instruments donot remain rigid so that the physician can apply a force using the sideor tip of the instrument, particularly when the tip is in the bentconfiguration.

It would be desirable to provide a reusable insertion instrument that isadjustably deflectable, but that can still remain rigid once it is bentor deflected so that a physician can apply pressure using the side ortip or the bent end section as necessary for various procedures.

SUMMARY

An insertion instrument is provided to address the issues with the priorknown devices, and in a preferred application, is particularly suitedfor ENT procedures, such as the insertion of a balloon into a nasalcavity.

The insertion instrument comprises a tube having a proximal end adaptedto be gripped by a user and a distal end adapted for insertion. A tipcontrol actuator is located at the proximal end, and the distal end ofthe tube includes a flexible portion. This flexible portion includes aspine and a plurality of circumferentially extending ribs extending fromthe spine. The ribs are axially spaced apart from a distal tip towardthe proximal end, with the ribs being spaced apart by wedge shapedpartial circumferential openings. A widest part of the wedge-shapedopenings is circumferentially opposite to the spine. The ribs have firstand second axial sides defined by the wedge-shaped openings, with thefirst axial side of one of the ribs facing the second axial side of anadjacent one of the ribs. For each of the ribs, at least one of thefirst or second axial sides includes at least one of an axiallyextending projection or a recess and a facing one of the at least one ofthe first or second axial sides of an adjacent one of the ribs includesat least one of a complementary mating recess or a corresponding axialprojection. At least one tension wire extends from the tip controlactuator to the distal tip. This allows a user, by actuating the tipcontrol actuator, to elastically bend/articulate the distal end of thetube to allow for insertion in a curved passage, such as a sinus cavity.At the same time, the projections enter or extend further into therecesses during bending of the distal end maintaining a rigid structure,allowing a sideways or normal force to be exerted by the tip as it isbeing inserted, which is often necessary in ENT procedures such asinserting a balloon, without the bent distal end of the tube shifting orcollapsing. This interlocking arrangement of projections and recessesalso provides a smooth inner surface that avoids tearing the balloonduring manipulation and insertion.

In a preferred arrangement, the tip control actuator comprises arotatable grip.

In a preferred arrangement, the tube comprises a guide tube connected toan end tube, with the end tube forming the distal end and including theflexible portion. This allows for the use of different materials for thetube, with each being optimized in terms of function and cost. Here, theend tube is formed of a superelastic material which allows for repeateduse of the insertion instrument. In a preferred application, the endtube is made of Nitinol and has a wall thickness of about 0.4-0.6 mm,and a diameter of about 3.2-3.6 mm. However, other sizes and wallthicknesses can be used depending on the particular application.

In a preferred arrangement, the axially extending projections andcorresponding complementary mating recesses and/or the recesses and thecorresponding axial projections in the plurality of ribs are arranged inat least one axially extending row. Preferably, there are at least tworows of the axially extending projections and correspondingcomplementary mating recesses and/or the recesses and the correspondingaxial projections. In one particularly preferred application, three ofthe axially extending rows of the axially extending projections andcorresponding complementary mating recesses and/or the recesses and thecorresponding axial projections are provided on the distal end, with afirst one of the rows being located approximately 80-100 degrees fromthe spine, a second one of the rows being located approximately 170-190degrees from the spine, and a third one of the rows being locatedapproximately 260-280 degrees from the spine. The recesses and/orcorresponding complementary mating recesses of the first and third rowshave a curved path extending from the at least one of the first andsecond axial sides toward the spine, and the projections and/orcorresponding axial projections of the first and third rows having acomplementary curved shape to the curved path of the respective recessesor corresponding complementary mating recesses. The recesses and/orcorresponding complementary mating recesses of the second row extendalong a straight axial path and the respective projections or thecorresponding axial projections have a complementary shape.

In a preferred arrangement, a clearance in a circumferential directionbetween axial projections and corresponding complementary matingrecesses and/or the recesses and the corresponding axial projections isabout 0.1-0.4 mm. This allows the bendable tip to be somewhat rigid to asideways or normal force, even when bent due to bracing of the axialprojections against the corresponding mating recesses and/or thecorresponding axial projections against the recesses.

In a preferred arrangement, at least one opening is provided in thedistal tip to connect the tension wire.

In a preferred arrangement, at least one of a complementary projectionor a mating recess is located in the distal tip facing the first side ofan adjacent one of the ribs. This allows for support and alignment ofthe distal tip with the distal-most rib.

In a preferred arrangement at least some of the axial projections are atleast partially located in the corresponding complementary matingrecesses or the corresponding axial projections are at least partiallylocated in the recesses, or both, in an unbent state of the distal endof the tube. This allows for better support, guidance, and alignment ofthe ribs relative to one another during bending.

In a preferred arrangement, upon application of a tension force on thetension wire, the distal tip is deflectable from an unbent state inwhich the distal tip remains aligned with an axis of the insertion tool,to an intermediate state in which the distal tip is aligned at an angleto the axis and at least some spaces remain between at least some of thefirst and second axial sides of the ribs, to a fully deflected state inwhich the first and second axial sides of the ribs contact one another.Preferably, in each of the unbent state, the intermediate state, and thefully deflected state, at least some of the axial projections arecircumferentially braced against sides of the correspondingcomplementary mating recesses and/or the corresponding axial projectionsare circumferentially braced against sides of the recesses to maintain arigidity of the distal tip relative to a normally applied force.

In one preferred arrangement, the wedge-shaped openings all have a sameshape. However, the shape of the wedge-shaped openings can be varied inorder to achieve a variable bend profile. The bend profile can also beadjusted based on an axial width of the ribs.

In one preferred arrangement, at least one of a complementary projectionor recess is provided in a part of the tube facing the second axial sideof a proximal-most one of the ribs.

In one preferred arrangement, the tip control actuator includes therotatable grip which has an internal thread, with the rotatable gripbeing axially fixed but rotatable on the tube. A sleeve with an externalthread is provided, with the sleeve being slideable on the tube and theexternal thread engaging with the internal thread of the rotatable grip.The sleeve further includes an axially extending slot, and a projectionconnected to the tube extends into the slot to prevents rotation of thesleeve. The at least one tension wire is connected to the sleeve, androtation of the rotatable grip causes an axial movement of the sleeve toapply tension on the distal tip via the tension wire in order toelastically bend the distal end.

In another aspect of the invention, a method of producing a bendable tipfor an instrument, is provided, which includes: mounting a tube for aninstrument in a CNC controlled rotational and axially movable holder ofa laser cutting machine, with a distal end of the tube extending fromthe holder; activating a laser cutter; cutting wedge shaped partialcircumferential openings in the tube to define a plurality of radiallyextending ribs at the distal end of the tube, with the ribs beingconnected together by an axially extending spine, and the ribs havingfirst and second axial sides; during cutting, forming in each of theribs in at least one of the first or second axial sides, at least one ofan axial projection or a recess, and forming in a facing one of the atleast one of the first or second axial sides of an adjacent one of theribs at least one of a corresponding complementary mating recess or acorresponding axial projection.

In a preferred method, the holder is hollow, and tube stock that is cutto form the bendable tip can be axially advanced out of the holder andthen cut to the desired tube length to form the tube, and a cuttingprocess for the next bendable tip can then be carried out on the newlycut end of the tube stock.

In a further preferred aspect of the method, during cutting, at leastone of a complementary projection or a mating recess is formed in anaxial side of the distal tip that faces the first axial side of a firstone of the ribs that is adjacent to the distal tip, with the at leastone of the complementary projection or the mating recess being alignedwith a corresponding one of the recess or the axial projection of afirst one of the ribs that is adjacent to the distal tip.

In a further preferred aspect of the method, during cutting, at leastone of a complementary projection or a mating recess is formed in anaxial side of a part of the tube facing the second axial side of a lastone of the ribs that is adjacent to a proximal part of the end tube,with the complementary projection or the mating recess being alignedwith the at least one of the recess or the axial projection on thesecond axial side of the last one of the ribs.

In a further preferred aspect of the method, in order to form theinsertion tool, a tension wire is connected to the distal end, and thetension wire extends through the tube to a tip control actuator locatedat a proximal end of the tube.

In a further preferred aspect of the method, during cutting, a clearanceof about 0.1-0.4 mm is created in a circumferential direction betweenthe axial projections and the corresponding complementary matingrecesses and/or the recesses and the corresponding axial projections.

In a further preferred aspect of the method, the end tube is formed froma superelastic alloy, preferably Nitinol.

In a further preferred aspect of the method, after the laser cutting, atleast one of electropolishing or abrasive cleaning of the tube isperformed. Here electropolishing is preferred due to the enhancedsmoothness of the surface finish obtained by this process and theability to treat all surfaces.

In a further preferred aspect of the method, during cutting, at leastone tension wire connection hole is formed at the distal end of the tubeopposite to the spine.

In a further preferred aspect of the method, during cutting, roundedopenings are formed at corners of the wedge shaped partialcircumferential openings adjacent to the spine. Preferably, theserounded openings are oval and have a major axis extending in the axialdirection of the tube.

As will be recognized by those of ordinary skill in the art from thepresent disclosure, the above-noted features can be utilized alone or invarious combinations in order to provide enhanced functionality forinsertion instruments.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary as well as the following Detailed Description willbe best understood when read in conjunction with the appended drawingswhich show a preferred embodiment of the invention. In the drawings:

FIG. 1 is perspective view of an insertion instrument in accordance withan embodiment of the invention.

FIG. 2 is a top view of the insertion instrument shown in FIG. 1.

FIG. 3 is a bottom, front perspective view of the insertion instrumentof FIG. 1.

FIG. 4 is a longitudinal cross-sectional view through the insertioninstrument of FIG. 1.

FIG. 5 is an enlarged perspective detail view of the distal end of theinsertion instrument of FIG. 1.

FIG. 6 is an enlarged elevational view of the distal tip of theinsertion instrument of FIG. 1.

FIG. 7 is an enlarged bottom perspective view of the distal tip of theinsertion instrument of FIG. 1.

FIG. 8 is a bottom plan view of the distal tip of the insertioninstrument of FIG. 1.

FIG. 9 is a greatly enlarged side elevational view of the distal tip ofthe insertion instrument of FIG. 1 along with a partial cross-sectionalview.

FIG. 10 is a side view showing the distal tip of the insertioninstrument of FIG. 1 shown in a partially bent position.

FIG. 11 is a side view of the distal tip of the insertion instrument ofFIG. 10 shown in a further bent position.

FIG. 12 is a side view of the insertion instrument of FIG. 10 shown in afully bent configuration.

FIG. 13 is a perspective view of a CNC controlled laser cutting machinehaving a rotational and axially moveable holder.

FIG. 14 is a flow chart showing a method for producing a bendable tipfor an insertion instrument.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “front,” “rear,” “upper” and “lower”designate directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” refer to directions toward and awayfrom the parts referenced in the drawings. The terms “approximately” and“about” are intended to cover manufacturing tolerances associated with aparticular dimension or range given. These terms and terms of similarimport are for ease of description when referring to the drawings andshould not be considered limiting. “Axially” refers to a direction alongthe axis of a shaft or similar object. A reference to a list of itemsthat are cited as “at least one of a, b, or c” (where a, b, and crepresent the items being listed) means any single one of the items a,b, or c, or combinations thereof. For the sake of convenience andclarity, the term “and/or” has been used in connection with descriptionof the interfacing projections and recesses so that it is clear that theprojections can be on either one of or both of two facing axial sides,and that the opposite one of or both of the two facing axial sides wouldinclude recesses in corresponding positions to the projections.

For elements of the invention that are identical or have identicalactions, identical reference symbols are used. The illustratedembodiments represent merely examples for how the device according tothe invention could be equipped. They do not represent a conclusivelimitation of the invention.

Referring to FIGS. 1-4, an insertion instrument 10 is shown. Theinsertion instrument 10 includes a tube 12 having a proximal end 14adapted to be gripped by a user and a distal end 16 adapted forinsertion. The insertion instrument 10 is preferably for use inconnection with ENT procedures, such as insertion of a balloon forexpanding a sinus cavity. However, it can be used for various othermedical or non-medical applications.

In the illustrated embodiment of the insertion instrument 10, the tube12 is formed of a guide tube 12A located at the proximal end that isconnected to an end tube 12B, located at the distal end. The end tube12B includes a flexible portion 30.

As shown in FIGS. 1-4, a tip control actuator 20 is located at theproximal end 14. This tip control actuator 20 comprises a rotatable grip22. However, other types of tip control actuators 20 could be utilized,such as an axially slideable grip.

Referring to FIG. 4, in one preferred application, the rotatable grip 22has an internal thread 23. The rotatable grip 22 is axially fixed butrotatable on the tube 12. A sleeve 24 with an external thread 25 isprovided, with the sleeve 24 being slideable on the tube 12 in an axialdirection and the external thread 25 of the sleeve 24 is engaged withthe internal thread 23 of the rotatable grip 22. The sleeve 24 furtherincludes an axially extending slot 26, and a projection 27 that isconnected to the tube 12 extends into the slot 26 in order to preventrotation of the sleeve 24 during turning of the rotatable grip 22. Atleast one tension wire 60, as discussed in further detail below, isconnected to the sleeve 24. A further description of the function of tipcontrol actuator 20 follows further below.

Still with reference to FIGS. 1-4 and with further reference to FIGS.5-8, the flexible portion 30 at the distal end 16 of the tube 12includes a spine 32 as well as a plurality of circumferentiallyextending ribs 34A-34I that extend from the spine 32 which are axiallyspaced apart from a distal tip 38 of the end tube 12B toward theproximal end. The ribs are generally referred to as 34, and the specificnumber of ribs 34A-34I could be varied depending upon the particularapplication for the insertion instrument 10 as well as the amount ofbend required from the flexible portion 30. As shown in detail in FIGS.5-8 and in further enlarged detail in FIG. 9, the ribs 34 are spacedapart by wedge-shaped partial circumferential openings 40. A widest part42 of these wedge-shaped openings 40 is located circumferentiallyopposite to the spine 32.

The ribs 34 have first and second axial sides 35, 36, best shown in theenlarged detail of FIG. 9. These axial sides 35, 36 are defined by thewedge-shaped openings 40, with the first axial side 35 of one of theribs, for example rib 34B, facing the second axial side 36 of anadjacent one of the ribs, for example rib 34A.

As shown in detail in FIGS. 5 and 9, rounded openings 44 are provided atthe corners of the wedge-shaped openings 40 adjacent to the spine 32.These rounded openings 44 are preferably oval, having a major axisextending in a direction of the axis X of the insertion instrument 10.

Still with reference to FIGS. 5-9, for each of the ribs 34, at least oneof the first or second axial sides 35, 36 includes one of an axiallyextending projection 50 or a recess 52, and a facing one of the at leastone of the first or second axial sides 35, 36 of an adjacent one of theribs 34 includes at least one of a complementary mating recess 51 or acorresponding axial projection 53.

As shown in detail in FIGS. 5-9, it can be seen that the first rib 34Aincludes three of the axially extending projections 50 on the secondaxial side 36 and the facing first axial side 35 of an adjacent rib 34Bincludes three of the complementary mating recesses 51. Additionally, ascan be seen most clearly in FIG. 8, the second axial side 36 of thefirst rib 34A includes a recess 52 and the first axial side 35 of thesecond rib 34B includes corresponding axial projections 53. While theillustrated embodiment includes both projections 20, 53 and recesses51,52 on both axial sides of the ribs 34, this is not required.

In a preferred embodiment, the axially extending projections 50 and thecorresponding complementary mating recesses 51 and/or the recesses 52and the corresponding axial projections 53 in the plurality ribs 34A-34Iare arranged in at least one axially extending low 55A, 55B, 55C,indicated in FIGS. 6 and 7. More preferably, there are at least two rows55A-55C of the axially extending projections 50 and the correspondingcomplementary mating recesses 51 and/or the recesses 52 and thecorresponding axial projections 53. In the illustrated embodiment, threeof the axially extending rows 55A-55C of axially extending projections50 and corresponding complementary mating recesses 51 and/or therecesses 52 and the corresponding axial projections 53 are provided.Here a first one of the rows 55A is located approximately 80°-100° fromthe spine 32. A second one of the rows 55B is located approximately170°-190° from the spine 32. A third one of the rows 55C is preferablylocated approximately 260°-280° from the spine 32. The recesses 52and/or the corresponding complementary mating recesses 51 of the firstand third rows 55A and 55C, and in the illustrated embodiment only thecomplementary mating recesses 51, preferably have a curved pathextending from the at least one of the first and second axial sides 35,36 toward the spine 32. This curved path is shown in detail in FIG. 9and preferably describes a radius R which generally corresponds to abend radius of the tube end 12B at the location of the recesses 51 inthe illustrated embodiment when it is being flexed. The projections, andin the illustrated embodiment only the axial projections 50, of thefirst and third rows 55A, 55C also have this complementary curved shapeto the curved path of the corresponding complementary mating recesses51.

Still with reference to FIG. 9, the axial projections 50 have aclearance in the circumferential direction of 0.1-0.4 mm with thecomplementary mating recesses 51. Similarly, the corresponding axialprojections 53 have the same clearance with the recesses 52. In the areaof the preferably curved path of the axial projections 50 and matingrecesses 51, preferably the axial projections 50 have a reducedinsertion area indicated at 56 where a width of the axial projection ismade smaller to allow for easier guidance and insertion of the axialprojection 50 as it enters the mating recess 51. In this area, theclearance can be greater than 0.4 mm. This also facilitatesmanufacturing.

As shown in detail in FIG. 8, preferably the recesses 52 and/or thecorresponding complementary mating recesses 51 of the second row 55 bextend along a straight axial path, and the respective projections 50 orthe corresponding axial projections 53 have a complementary shape.

While one preferred arrangement of the axial projections 50 and matingrecesses 51 along with the recesses 52 and the corresponding axialprojections 53 is shown, those skilled in the art will recognize thatother configurations could be utilized and that these projections andrecesses do not need to be arranged in rows as illustrated.

In the preferred arrangement, the end tube 12B is formed of superelasticmaterial, such as Nitinol. Preferably, for us in ENT applications forinsertion of a balloon catheter, the end tube 12B has a wall thicknessof about 0.4-0.6 mm, and a diameter of 3.2-3.6 mm. Those skilled in theart will recognize that these dimensions can be changed for otherapplications and that other suitable materials may be utilized.

As shown in FIGS. 8 and 9, preferably at least one opening 39 isprovided in the distal tip 38 to connect a tension wire 60. As shown inFIG. 4, at least one tension wire 60 extends from the tip controlactuator 20 to the distal tip 38 where it is anchored in the at leastone opening 39. In one preferred embodiment, two of the tension wiresare provided in order to maintain a reduced cross-sectional diameter ofthe tension wires that projects into the clear open cross-section of thetube 12B while still carrying the necessary loads from the tip controlactuator 20 to the distal tip 38 required for elastically bending theflexible portion 30 at the distal end 16 of the tube 12.

As shown in detail in FIGS. 5-9, at least one of a complementaryprojection 53T or a mating recess 51T is located in the distal tip 38facing the first axil side 35 of an adjacent one of the ribs 34A.Further, as shown in detail in FIGS. 5-8, preferably at least one of acomplementary projection 53P or recess 52P is provided in a part of thetube 12B facing the second axial side 36 of a proximal-most one of theribs 34I. This is preferably provided in order to provide continuity inthe ability to transfer normal forces against the flexible portion 30 ofthe distal end 16 of the tube 12 when it is in the flexed or bentposition as discussed in further detail below.

Still with reference to FIGS. 5-9, preferably at least some of the axialprojections 50 are at least partially located in the correspondingcomplementary mating recesses 51 and/or the corresponding axialprojections 53 are at least partially located in the recesses 52 in anunbent state of the distal end 16 of the tube 12. This partial overlapensures a smooth bending of the flexible portion 30 of the tube 12 whenthe tip control actuator 20 is actuated by a user.

Referring to FIGS. 9-12, upon application of a tension force on thetension wire 60 using the tip control actuator 20, the distal tip 38 isdeflectable from an unbent state in which the distal tip remains alignedwith the axis X of the insertion tool 10, to one or more intermediatestates as shown in FIGS. 10 and 11, in which the distal tip 38 isaligned at an angle to the axis X and at least some space remainsbetween at least some of the first and second axial sides 35, 36 of theribs 34, to a fully deflected state, as shown in FIG. 12, in which thefirst and second axial sides 35, 36 of the ribs 34 contact one another.In each of the intermediate state and the fully deflected state, atleast some of the axial projections 50 are circumferentially bracedagainst sides of corresponding complementary mating recesses 51 and/orthe corresponding axial projections 53 are circumferentially bracedagainst sides of the recesses 52 to maintain a rigidity of the distaltip 38 relative to a normally applied force on the distal tip 38. Thisis important for certain ENT applications where a normal force must beapplied when the distal tip 38 is in the deflected position in order topush tissue out of the way as the insertion instrument 10 is advancedinto a body cavity such as a sinus cavity.

In order to provide different bend profiles for the flexible portion 30,the wedge-shaped openings 40 may all have the same shape, as illustratedin detail in FIGS. 6 and 9. Alternatively, at least some of thewedge-shaped openings 40 may have different shapes to provide a variablebend profile. This can be done by varying the angle α indicated in FIG.9 on some of the ribs at different locations. Alternatively, as isapparent from FIG. 10, some of the ribs 34 may have different widthswhich can also be used to adjust the bend profile.

In use, particularly for the embodiment of the insertion instrument 10with the rotatable grip 22 that is shown in detail in FIGS. 1-4, inorder to insert the insertion instrument 10 into a body cavity, such asa sinus cavity of a patient, the operator rotates the rotatable grip 22in order to apply tension via the at least one tension wire 60 to thedistal tip 38 such that the flexible portion 30 elastically bends intoone or more of the intermediate or fully deflected states such asillustrated in FIGS. 10-12 in order to allow the operator to advance theinsertion instrument 10 into the desired sinus cavity. Then, aninstrument can be inserted through the tube 12, into the sinus cavity.This has particular application in connection with the insertion of aballoon catheter into a sinus cavity.

Referring now to FIGS. 13 and 14, a method for producing a bendable tipfor an instrument 10 is also provided. The method includes mounting atube 12 for the instrument in a CNC controlled rotational and axiallymoveable holder 102 of a laser cutting machine 100. This step isgenerally indicated at 110 in FIG. 14. One example of such a lasercutting machine is the Quantum-Cut Tube machine available from BlueacreTechnology Ltd. of Louth, Ireland which provides a high accuracy fouraxis cutter that allows for cutting and profiling of tubes. Preferably,the moveable holder 102 includes a hollow chuck and long lengths of tubestock may be provided by inserting the tube stock through the chuck suchthat only a small portion of the tube is exposed for laser cutting. Thelaser 104, shown in FIG. 13, is then activated, as indicated in FIG. 14at 112. The CNC controlled moveable holder then rotationally and axiallymoves the tube under the laser cutter in order to cut the wedge-shapedpartial circumferential openings 40 (as shown in FIG. 9) in the tube 12to define the plurality of ribs 34 which extend axially from the distalend of the tube 12. As discussed above, the ribs 34 are connectedtogether by the axially extended spine 32. This is indicated at 114 inFIG. 14. During cutting, at least one of an axial projection 50 or arecess 52 is formed in each of the ribs in at least one of the first orsecond axial sides 35, 36. This is indicated at 116 in FIG. 14. Further,during cutting, at least one of a corresponding complementary matingrecess 51 or a corresponding axial projection 53 is formed in a facingone of the at least one of the first or second axial sides 35, 36 of anadjacent one of the ribs 34. This is indicated at 118 in FIG. 14.

Preferably, during cutting, the complementary projections 53T or matingrecesses 51T are formed in an axial side of the distal tip 38 that facesthe first axial side 35 of a first one of the ribs 34A, and at least oneof the complementary projections 53T or mating recesses 51T is alignedwith a corresponding one of the recesses 52 or the axial projection 50of the first one of the ribs 34A adjacent to the distal tip 38.

Further, during cutting at least one complementary projection 53P or amating recess 51P is formed in an axial side of a part of the tube 12facing the second axial side 36 of a last one of the ribs 34I that isadjacent to the proximal part of the tube 12. The complementaryprojection 53P or the mating recess 51P is aligned with the at least oneof the recess 52 or the axially projection 50 on the second axial side36 of the last one of the ribs 34I.

During cutting of the axial projections and mating recesses, a clearancein the circumferential direction of about 0.1-0.4 mm is provided inorder to provide for smooth bending operation of the flexible portion 30while still allowing the bracing contact between the respectiveprojections and the recesses so that a normal force can be applied tothe distal end 38 in use without the flexible portion 30 at the distalend 16 of the tube 12 collapsing or flexing. This is indicated at 120 inFIG. 14.

Preferably, during cutting, a tension wire connection opening 39 isformed at the distal end 16 of the tube circumferentially opposite tothe spine 32. This allows connection of the tension wire 60 to thedistal tip 38 in a later step. This is indicated at 122 in FIG. 14.

Preferably, during cutting, rounded openings 44 are formed at thecorners of the wedge-shaped partial circumferential openings 40 adjacentto the spine 32. This is indicated at 124 in FIG. 14.

Once the cutting of the tube 12 is completed, to the extent that this isonly a portion of a longer piece of tube stock from which multiple suchtubes 12 can be formed, the tube stock is advanced through the moveableholder 102 until a sufficient length is exposed to form the desiredlength for the tube 12 and the completed tube 12 is cut from the end ofthe tube stock. At that point the next cutting operating for forming thenext tube 12 can be initiated.

Once cutting of the tube 12 has been completed, it is preferably atleast one of electropolished or abrasively cleaned in order to removeany sharp edges and smooth over any imperfections in the areas of thelaser cutting. Electropolishing is preferred due to the smooth surfacefinish provided which does not include any abrasive scratch lines due tothe electropolishing process used. Alternatively, depending on theparticular application for the instrument 10, an abrasive cleaning, forexample, in a shaker with an abrasive media could also be utilized.

Once the tube 12 is complete, or if the only portion formed using lasercutting is the end tube 12B, this can be assembled with the guide tube12A to complete the tube 12, and then the tip control actuator 20 can beassembled to the tube 12. The at least one tension wire 60 is thenconnected from the at least one connection opening 39 and extendedthrough the tube 12 for connection to the tip control actuator 20.

The insertion instrument 10 then provides the advantage of not requiringseparate tips having different bend angles since the construction of theflexible portion 30 is specifically designed to allow for theapplication of a normal force without the distal tip 38 being undulydeflected in a manner that would hinder the insertion process,particularly in ENT applications.

Having thus described the present invention in detail, it is to beappreciated and will be apparent to those skilled in the art that manyphysical changes, only a few of which are exemplified in the detaileddescription of the invention, could be made without altering theinventive concepts and principles embodied therein. It is also to beappreciated that numerous embodiments incorporating only part of thepreferred embodiment are possible which do not alter, with respect tothose parts, the inventive concepts and principles embodied therein. Thepresent embodiment and optional configurations are therefore to beconsidered in all respects as exemplary and/or illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description, and all alternateembodiments and changes to this embodiment which come within the meaningand range of equivalency of said claims are therefore to be embracedtherein.

The invention claimed is:
 1. A method of producing a bendable tip for aninstrument, comprising: mounting a tube for an instrument in a CNCcontrolled rotational and axially movable holder of a laser cuttingmachine, with a distal end of the tube extending from the holder;activating a laser cutter; laser cutting wedge shaped partialcircumferential openings in the tube to define a plurality of radiallyextending ribs at the distal end of the tube, the ribs being connectedtogether by an axially extending spine, and the ribs having first andsecond axial sides; during the laser cutting, forming in each of theribs in at least one of the first or second axial sides, at least one ofan axial projection or a recess, and forming in a facing one of the atleast one of the first or second axial sides of an adjacent one of theribs at least one of a corresponding complementary mating recess or acorresponding axial projection, wherein the at least one of the axialprojection and the corresponding complementary mating recess or therecess and the corresponding axial projection formed in each of the ribsare arranged in first, second and third axially extending rows spacedfrom the spine, wherein the recesses and corresponding complementarymating recesses of the first and third rows have a curved path extendingfrom the first and second axial sides toward the spine and the axialprojections and corresponding axial projections of the first and thirdrows having a complementary curved shape to the curved path of therespective recesses and corresponding complementary mating recesses, therecesses and corresponding complementary mating recesses of the secondrow extending along a straight axial path and the respective axialprojections and corresponding axial projections having a complementaryshape.
 2. The method of claim 1, further comprising: connecting at leastone tension wire to the distal tip; and extending the at least onetension wire through the tube to a tip control actuator located at aproximal end of the tube.
 3. The method of claim 1, further comprising:creating a clearance in a circumferential direction of about 0.1-0.4 mmbetween the axial projections and the complementary mating recessesand/or the recesses and the corresponding axial projections.
 4. Themethod of claim 1, further comprising: forming the tube from a shapememory alloy.
 5. The method of claim 4, wherein the shape memory alloyis Nitinol.
 6. The method of claim 1, further comprising: after thelaser cutting, at least one of electropolishing or abrasive cleaning ofthe tube.
 7. The method of claim 1, further comprising: during the lasercutting, forming a tension wire connection opening at the distal end ofthe tube circumferentially opposite to the spine.
 8. The method of claim1, further comprising: during the laser cutting, forming roundedopenings at corners of the wedge shaped partial circumferential openingsadjacent to the spine.
 9. The method of claim 8, wherein the roundedopenings are oval having a major axis extending in the axial directionof the tube.
 10. The method according to claim 1, wherein the tube is apart of a length of tube stock, and the method further comprising:mounting the tube stock in the CNC controlled rotational and axiallymovable holder, and after the laser cutting, advancing the tube stockthrough the moveable holder until a sufficient length is exposed to forma desired length for the tube, and cutting the tube from an end of thetube stock.
 11. The method according to claim 1, wherein the lasercutting further comprises laser cutting the wedge shaped partialcircumferential openings with different shapes to provide a variablebend profile.
 12. The method according to claim 1, wherein the tube isan end tube, and the method further comprising assembling the end tubewith a guide tube.
 13. The method according to claim 1, furthercomprising assembling a tip control actuator to the tube.